For some reason, when using the tonumber() function on a string containing a negative number, starting with "-0.", it returns the absolute value of that number. This happens with any negative number -1 < x < 0, and only when the zero is given before the decimal point in the string.

To reproduce:

Open Lua Engine window, and type: print(tonumber("-0.028"))

Then click Execute. It will say "0.028", while it should say "-0.028".